Hi All

For me RouterOS is impossible to configure. But I have bought a CRS switch which somehow I have to use it.

I am thinking of using it's SwOS and configuring it as a pure L2 switch. I have the following queries regarding it.

1. I have learnt that RouterOS uses switch chip, to offload l2 functions to the switch chip. In SwOS it does not. Will I have the degraded performance because of it?
2. Can I get the same wire speed with SwOS?
3. Does SwOS has VLAN0 as the native VLAN, instead of VLAN1?

Thanks.

SwOS is only a tool to configure the switch chip. It does not use CPU to forward frames => everything is wirespeed.

VLAN 0 does not exist in general - VLAN ID 0 is a reserved value which, if present in an 802.1Q tag of an ingress frame, means "as for the VLAN ID, treat the frame as if it was untagged (i.e. assign it the VLAN ID indicated by the pvid setting of the ingress port), but take into account the three bits indicating the priority".

So if I use SwOS on my CRS326-24S-2Q+RM, it will give me the full speed 24x10 + 2x10Q at wire speed?

Yes.

So if I have a core switch with Native VLAN 1, will SwoS has to adjust to it? or what change should I do?[/b]

The term "native VLAN" is relevant for a particular port. If a frame that belongs to VLAN 1 egresses through a port whose native VLAN is 1, the VLAN tag gets stripped and the frame is sent to the wire without it. Vice versa, if a frame with no VLAN tag arrives through the wire, it gets tagged and the VLAN ID is set to the "native VLAN" of that port as it ingresses to the switch.

So in SwOS, you have to set up the native VLAN of the port you connect to a port of the core switch whose native VLAN is 1 also to 1.

Thanks for the help ad explanation.

How to se the Native VLANs in RouterOS and SwOS?

Thanks again.

How to se the Native VLANs in RouterOS and SwOS?

Strictly speaking, a "native" VLAN is the only VLAN permitted on a port classified as an "access" one, so the very name "native" only has a distinctive meaning on a "trunk" (in "Ciscoish") or "hybrid" (in "HPish") port.

Hence for SwOS, this Trunk and Hybrid Ports section of the manual is the right place to look.

For RouterOS, the actual information that needs to be entered is the same, but the way to enter it is slightly different. There are two tables - /interface/bridge/port, which defines the membership of interfaces in bridges as ports, and /interface/bridge/vlan, which defines the details of membership of the bridge ports in the VLANs on their bridges.

Using the /interface/bridge/port table, you can choose whether an Ethernet interface will be treated as a member port of some bridge or not, and if yes, the place to set the ID of the native VLAN is the pvid column on the row in that table. This is all you need to do to add a bridge port with a native VLAN N - the addition of an interface to a bridge by means of the row in that table and setting the pvid on that row to N automatically creates a dynamic row in the /interface/bridge/vlan table unless it has already been present there, the vlan-ids column of that row gets set to N, and the interface gets placed to the list in the untagged column of that row. If the interface already has been a member of a bridge and had some native VLAN assigned, by changing the pvid you just change the native VLAN.

If a row with vlan-ids=N has already been present in the /interface/bridge/vlan table for a given bridge and you make another interface a member port of the same bridge with pvid set to N, the interface is only added to the untagged list on that row. But if a row has been manually added for that bridge and N is just one of the VLAN IDs in the vlan-ids list on that row, the system will not resolve such a conflict (at most one VLAN can be the native one for any given port) automatically, nor will it resolve the case when N is the only item on the vlan-ids list of a row but the interface has been added to the tagged list on that row.

So start from simple cases (as in "create access ports to individual VLANs"), then move to pure trunk ports (that have no native VLAN, which means you have to set ingress-filtering to yes and frame-types to admit-only-vlan-tagged on the /interface/bridge/port row, so the pvid column on that row will be ignored and the interface will not be added to the untagged list of any row in /interface/bridge/vlan, but you will have to manually add rows to /interface/bridge/vlan and put the interface names to the tagged lists on those rows), and finally you can set up "hybrid" ports that allow multiple VLANs to pass through, one of them "native".